As a common acoustic-electric transducer for converting electrical power into acoustic energy, the speaker is crucial in the sounding system. There is a variety of speakers, by which audio cones or diaphragms vibrate and resonate with the surrounding air to make sound through electromagnetic effect, piezoelectric effect or electrostatic effect. Thus, it is difficult to imagine how to enjoy wonderful sounding effects without the speaker.
Currently none of the commercial speakers is manufactured by wafer process or MEMS technology. While conventional speakers have been struggling in further scaling-down as requested by main-stream consumer customers, MEMS speakers on the other hand which is expected to play an important role in further miniaturized speaker market, has encountered fabrication cost problem in making large enough diaphragm for sufficient sound level output.
On one hand, the prior MEMS speaker is manufactured by wafer process and magnet integration, which makes the manufacturing process of the speaker extremely complicated and costly. Besides, the connecting pieces for connecting respective components of the speaker is mostly made of fragile materials/structures which, however, are unable to bear large deformation, thereby deteriorating the quality and service life of the speaker.
On the other hand, the prior MEMS speaker is a miniaturized digital speaker which requires a complicated high voltage integrated circuit (MEMS) to drive itself, while the diaphragm is susceptible to the impact from the digital switch of the digital miniaturized speaker , thereby reliability and service life might be big concerns.
Generally speaking, the prior speaker has the following problems:
1. Conventional speaker technologies have encountered challenges in further size-down and cost-down as requested in most of the consumer market.
2. The application of MEMS technology to the speaker seems struggling with fabrication cost and reliability issues.
3. The manufacturing cost of the MEMS speaker is kept high due to the complicated wafer process.